But although he's the youngest of the trio, Lautner is arguably the most relaxed during the interviews.
The buff-looking 20-year-old, who's played werewolf Jacob Black in all five films, reflects on the end of the franchise: "I think there's mixed emotions for everyone.
"It's a bummer it's coming to an end and it's going to be tough to say goodbye, but at the same time it's exciting to get this last one out there and have the fans see it and wrap up the franchise."
Lautner, who hails from Michigan, admits he was entirely unfamiliar with Twilight before being cast.
"I'd never even heard of the books and then after we made the first movie we were hoping that some of the people who'd enjoyed the books would enjoy the movie.
"But we had no idea it would turn out like this, not in my wildest imagination," he says.
As close as he is to Stewart and Pattinson now, he remembers it being tricky in the early days. "It was strange because I was barely in Twilight so I showed up halfway through filming and everybody knew each other.
"I was kind of the new kid on the block so it started off a little bit awkward but that soon changed," he reveals.
But he still can't look at those early images of himself wearing Jacob's mullet wig.
"Whenever someone shows me a picture of it I'm like, 'Argh'. It's tough to look at that!"
He also revealed that now the saga is concluded, he can't wait to keep his shirt on for a change.
The 20-year-old has become known for going shirtless and showing off his toned physique, but admitted that he was able to reduce the number of times that happens in the final film, Breaking Dawn - Part 2.
"I'm looking forward to saying goodbye to that for sure. I was able to tame the numbers of the shirt coming off quite a bit. It only comes off once in this so that was nice," he said.
Having grown up on screen, Lautner says he hopes he hasn't changed too dramatically from the person he was before shooting began.
"I hope we haven't changed who we are as people throughout this time and I hope the people who know me best say that about me," he says.
"I can absolutely say that about my fellow castmates. They're the same people today who they were before any of this and that's amazing."